In this paper, the authors discuss the concepts of variability, buffers, and batches, as well as the interactions between them. The discussion aims at contributing to the identification of factors that impact production systems design, which includes the definition of buffer locations, buffer profiles, batch sizes, etc. The authors use a simulation model developed using STROBOSCOPE to represent five different scenarios for planning, fabrication, shipping, and installation of sheet metal ductwork in order to illustrate how production system design choices may affect the lead time needed to deliver a project. The data used to develop the model was obtained from time studies performed by the authors as well as from interviews conducted with field superintendents. In order to develop the model, the authors needed basic information about activities pertaining to the delivery of sheet metal ductwork. Modeled durations and quantities are approximations based on the data collected. The model highlights the need for and importance of reliable data when designing production systems and simulation models thereof. Effort needs to be put in by the construction industry and researchers to gather more representative sets of data that can be used to design production systems.
Simulation, production system design, buffers, batches.